Wildlife officials carry away the carcass of a turtle that was washed ashore at the beach of Angulana, south of Sri Lanka's capital Colombo on June 24, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

Australia's Nicholas Timmings competes in the men's Skeleton World Cup in Altenberg, eastern Germany, on December 3, 2021. (Photo by Tobias Schwarz/AFP Photo)

Wild deer rummage through garbage dumped at an open ground in Sri Lanka's district of Trincomalee on April 4, 2023. (Photo by Ishara S. Kodikara/AFP Photo)

A woman poses for a picture during Lunar New Year's Eve on Yaowarat Road in Bangkok's Chinatown, Thailand, February 9, 2024. (Photo by Jorge Silva/Reuters)

Everyone wants to get something for nothing - whether it's a lucky upgrade that means you can turn left when you get on a plane instead or heading off into the economy seats, or even getting a few extra features thrown in for free when you buy a new car.

As some of the sharpest businesses around, no-one understands this quite as well as casinos and that's why they all have a system that they call comps. It's short for "complimentary offers" and these are special treats specially designed to reward you for your loyalty to the casino in question. They're basically bonuses.

Germany's Kira Walkenhorst (L) taps Germany's Laura Ludwig during the women's beach volleyball qualifying match between Germany and Canada at the Beach Volley Arena in Rio de Janeiro on August 9, 2016, for the Rio 2016 Olympic Games. (Photo by Leon Neal/AFP Photo)

Victoria's Secret Angel Martha Hunt celebrates the 2015 What Is s*xy? List in San Diego on September 26, 2015 in San Diego, California. (Photo by Joe Scarnici/Getty Images for Victoria's Secret)

Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)